The present invention concerns an intracorporal drive for producing a continuous traction or pressure, respectively, especially for an extension unit intended for extension osteotomy or for a compression unit intended for pressure osteosynthesis, and to method of operation thereof.
Drives, for instance for an extension unit for extension osteotomy comprising two telescopically adjustable parts which, after having cut the bone, are both separately screwable to the bone to be extended and which are prevented from backward movement, are known in various constructions. German Pat. No. 2,417,233 discloses, for example, a motor drive disposed in the extension unit which is controlled by electrotechnical means. Such a drive is comparatively expensive and requires a highly specified outer covering in order to prevent any contact with the surrounding tissue. The use of a pressure gas drive, which is also described in the above mentioned German patent publication, is rather problematic, because a strong intracorporal pressure wave could be produced in case of breakage of the extension unit.